Electrical connector



June 22, 1943. E. DEHMEL' EL ECTRIYCAL CONNECTOR Filed July 10, 1941 Inventor: I Erich Dehmel by His Attorneg.

Patented June 22, 1943 ELECTRICAL CONNECTOR Erich Dehmel, Berlin, Germany, assignor to General Electric Company, a corporation of New York Application July 10, 1941, Serial No. 401,834 In Germany June 13, 1940 4 Claims.

My invention relates to an electrical connector and more specifically to an electrical connector for electrically connecting a stationary and a movable current conductor.

Heretofore, electrical connectors for providing a good current-conducting path between a stationary and a movable electrical conductor have comprised laminated or flexible copper conductors or shunts. Such flexible shunts have been used with circuit breakers of various kinds and, in connection with short circuits, diiiiculties were encountered in that they sometimes burned ofi. Also, the magnetic forces due to heavy short circuits have torn copper ribbon or copper braided shunts from their fastenings. Furthermore, although copper is suitable for making flexible shunts in view of its mechanical strength as well as its good electrical conductivity and resistance against corrosion, if flexible electrical shunts either braided or laminated were to be made of aluminum, for example, certain difiiculties would result. Although the conductivity of aluminum is very good, mechanically thin bands or strands of aluminum would break under repeated bending as would occur in a flexible shunt.

Accordingly, it is an object of my invention to provide a new and improved electrical connector for insuring satisfactory electrical connection between a stationary and a movable conductor.

It is another object of my invention to provide a new and improved electrical connector which will function as a flexible shunt and which may be constructed of aluminum if desired.

Further objects and advantages of my invention will become apparent as the following description proceeds and the features of novelty which characterize my invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.

For a better understanding of my invention, reference may be had to the accompanying drawing in which Fig. 1 is a side View of an electrical connector for electrically interconnecting a stationary and a movable current conductor, Fig. 2 is a front View partly in section of the electrical connector of Fig. 1, Fig. 3 is a schematic diagram showing an application of my invention to an electrical device, and Figs. 4 and 5 are modifications of the electrical connector shown in Figs. 1 and 2.

Referring now to Figs. 1 and 2, I have illustrated two current conductors I and 2 having the ends thereof bent so as to form a curvilinear surface. The outer diameters of the bent or curved portions of conductors I and 2 constitute the current-transmitting, rolling surfaces I and 2', respectively. In order that conductors I and 2 are continually maintained in good current-conducting relationship, I have provided a cage 3 having a pair of longitudinally arranged slots 3 therein. A U-shaped strap 4 is provided for supporting a roller 6, and the axle 6' of this roller passes through the longitudinal slots 3' in cage 3. A second roller 5 is supported on a fixed pivot in cage 3 and the curved portions of conductors I and 2 are inserted between rollers 5 and 6 as clearly shown in Figs. 1 and 2. In order to maintain the curvilinear rolling contact surfaces I and 2' of these conductors in good current-com ducting relationship, I provide springs I for biasing U-shaped strap 4 upwardly in cage 3, the axle 6' of the roller 6 being movable in the longitudinal slots 3' in cage 3. In order to improve the current-conducting ability at the curvilinear surfaces I and 2' of conductors I and 2, each of these conductors is preferably provided as shown in Fig. 2 with a layer or surface 8 of material which has a high electric conductivity. Silver, for example, has been used extensively for contact surfaces since it is a good electrical conductor and the oxide is both physically and chemically unstable so as to be either decomposed or rubbed off by high-contact pressures, thereby providing substantially no impedance to the flow of electric current.

It will be observed that, with the arrangement disclosed in Figs. 1 and 2, one or more of the conductors I and 2 may be rotated about the axis of the rollers 5 and 6. Preferably, however, the end of one of the conductors I and 2 is stationary while the end of the other conductor is movable. In all of these positions, the curvilinear surfaces I and 2 of conductors I and 2 are firmly pressed into good current-conducting engagement with one another so as to insure a highly satisfactory transfer of current. With this arrangement also, I have provided an electrical connector between a stationary and a movable current conductor which operates as satisfactorily as a flexible shunt and eliminates the inherent disadvantages of the latter.

In Fig. 3, I have illustrated an application of my invention to the movable contact of an electric circuit breaker, only the movable contact of which is shown. Accordingly, in Fig. 3, a contact-supporting arm 9 pivotally mounted at It to fixed support I! carries at its free end a rolling contact element l0 which is pivotally mounted to contact-supporting arm 9 at I2. The rolling contact element I0 supports the movable contact l l which cooperates with the stationary contact of a circuit breaker, not shown. The contact pressure of the contact II against the stationary contact, not shown, is controlled by means of a compression spring 14 mounted between the extension l5 of rolling contact member In and the extension 13 of contact-supporting arm 9. In order to insure good electrical interconnection of fixed support or conductor l1 and movable contact I I, the rolling contact element In is provided with a curvilinear conducting surface It) as is also the fixed support 11 provided with the curvilinear surface l'i'. Between these curvilinear surfaces IB' and I1, I provide a solid. 8- shaped conductor l8 including curvilinear surfaces lB' at each end thereof for serving as the rolling contact surfaces for engaging with the curvilinear surfaces I and I1, respectively. In order to maintain the curvilinear surfaces l6 and It" in good current-conducting relationship, a suitable cage I9 pivotally mounted to rolling contact member In at 20 is provided. A pin or roller 2! engages one of the curved ends of S- shaped member l8 as illustrated in Fig. 3 and is spring biased by spring 22 into good conducting engagement to cause good electrical contact between surfaces l5 and i8, respectively. In the same manner, a cage I9 is pivotally supported by pivot l6 and a spring 22' is provided to bias pin 2 l against the curved end of S-shaped conductor I8 to provide a good rolling contact surface between the curvilinear surface ll of support I! and the corresponding surface l8 of conductor l8.

If the contact-supporting element 9 of Fig. 3 is moved to the dotted position indicated in the drawing, the rolling surfaces Ill and I8 and II and I3 will roll one on the other to insure good electrical contact between stationary conductor I1 and movable rolling contact element 10 without the necessity of a flexible shunt and its inherent disadvantages.

In Figs. 4 and 5, I have illustrated a modification of the construction of Figs. 1 and 2 and the corresponding parts thereof are designated by the same reference numerals. Instead of the rollers 5 and 6 providing a guide for the conductors l and 2 as in Figs. 1 and 2, the inner surface of the curved ends of conductors I and 2 are provided with a recess 23 within which the rollers 5 and 6 are adapted to be guided. The operation of the arrangement illustrated in Figs. 4 and 5 is identical with that shown in Figs. 1 and 2.

It should be understood by those skilled in the art that the rolling surfaces maybe spherically mounted to eliminate the necessity of special guides, if desired.

While I have shown and described particular embodiments of my invention, it will be obvious to those skilled in the art that various changes and modifications may be made without departing from my invention and I, therefore, aim in the appended claims to cover all such changes and modifications.

I claim:

1. In combination, a movable electric current conductor having a curvilinear surface at one end thereof, a stationary electric current conductor having a curvilinear surface at one end thereof, an electrical connector for interconnecting said conductors comprising means for causing said curvilinear surfaces to make rolling contact with each other, and spring means for biasing said curvilinear surfaces into good current conducting engagement regardless of the movement of said movable contact.

2. In combination, a movable electric current conductor having a curvilinear surface at one end thereof, a stationary electric current conductor having a curvilinear surface at one end thereof, means for electrically interconnecting said movable and stationary conductors comprising a cage having a pair of rollers mounted therein, one of said rollers being movable relative to the other, the curvilinear surfaces of said conductors being held in rolling engagement with each other between said rollers, and means-for biasing said one roller toward said other roller to bias said curvilinear surfaces into good current-conducting engagement throughout the rolling movement between the same when said movable conductor moves relative to said stationary conductor.

3. In combination, a movable electric current conductor having a curvilinear surface at one end thereof, a'stationary electric current conductor having a curvilinear surface at one end thereof, means for electrically interconnecting said movable and stationary conductors comprising a cage having a pair of rollers mounted therein, one of said rollers being movable relative to the other, the curvilinear surfaces of said conductors being held in rolling engagement with each other between said rollers, means for biasing said one roller toward said other roller to bias said curvilinear surfaces into good currentconducting engagement throughout the rolling movement between the same when said movable conductor moves relative to said stationary conductor, and guide means for guiding the movement of said conductors relative to said rollers.

4:. In an electrical connector between a stationary and movable current conductor each having a curvilinear surface thereon and arranged so that said curvilinear surfaces are in rolling engagement with one another, means for insuring efficient current transfer between said rolling contact surfaces including a cage having a first roller mounted on a fixed pivot in said cage, a longitudinal slot in said cage, a second roller having an axle movable in said longitudinal slot so as to move toward and away from said first roller, said conductors being mounted between said rollers with said curvilinear surfaces in rolling contact with one another, and spring means for biasing said second roller toward said first roller to insure good currentconducting engagement between said curvilinear surfaces regardless of any movement of said movable conductor.

ERICH DEHMEL. 

